Unenhanced Magnetic Resonance Portography Using Repetitive Arterial or Vein Labeling Method at 3.0-T

Abstract

Objective: The objective of this study was to determine whether unenhanced magnetic resonance (MR) angiography using repetitive arterial or vein labeling (RAVEL) is feasible to visualize effectively the intrahepatic portal vein (PV) at 3.0 T. Methods: Forty patients underwent liver MR imaging (MRI) with unenhanced MR portography using RAVEL. Two radiologists performed a consensus review of unenhanced MR portography and portal-phase MRI with regard to anatomic type of PV, vessel conspicuity, and image quality. Results: For determination of the anatomic type of PV, the 2 techniques were equivalent. There were tendencies toward increased conspicuity for right segmental PV and its branches with unenhanced MR portography and for left PV with conventional MRI, although significant differences were not found between MRIs (P < 0.05). Image quality for unenhanced MR portography was poor in 1, moderate in 8, and good in 31 patients. Conclusions: Unenhanced MR portography using RAVEL at 3.0 T is feasible and provides effective visualization of intrahepatic PV. Key Words: liver, MR angiography, unenhanced MR portography, arterial spin labeling